Plastic lenses, glass lenses, and silicone lenses often perform the same function in optical systems, such as in cameras, automotive lighting, military night vision equipment, and, particularly, LEDs (Light Emitting Diodes). The main attributes that separate plastic lenses from glass lenses are lower weight, better impact resistance, and lower cost. Glass, however, is more stable at very high temperatures. The difference in cost is due largely to the difference in manufacturing processes that are required for the two materials and the relative temperatures required to form the materials. Plastic lenses are typically produced at about 230-390° C. using injection molding at cycle times that are about 10 times faster than glass lenses. Glass lenses are typically produced using grinding and polishing or compression molding at about 625° C. Silicone lenses have very high temperature resistance, yet are more expensive to produce than glass. Silicone materials typically cost at least about 3-5 times as much as glass and plastic materials, and require costly molds for either compression molding or liquid injection processing which are performed at relatively slow production rates. It is easier and less expensive to mold special details into plastic lenses than glass and silicone lenses.
Industrial lens devices, such as camera lens and LED lens devices, are typically assembled in solder reflow ovens. Traditionally, lead has been used as an ingredient in the solder to reduce the melting temperature of the solder to just under about 200° C. The problem is that it is often desirable to use lead free solder and the temperature required to melt lead free solder may be about 217° C. or higher. This has led to the requirement of solder reflow ovens that operate at higher temperatures with operating temperatures that typically peak at about 250-285° C. The increase in the processing temperatures for solder reflow ovens has created the need for injection moldable, optically clear thermoplastics that have significantly higher glass transition temperatures (Tg). This invention provides a solution to this problem.